A known drive system includes an electric cooling water pump and an electric cooling fan that are driven by individual motors to cool down an engine, and a control unit that controls the operations of the individual motors of the electric cooling water pump and the electric cooling fan (see, for example, Japanese Utility Model Laid-Open Gazette No. H06-34131). When the temperature of cooling water is still high at the timing of the operator's OFF operation of an ignition switch for system-off, the individual motors of the electric cooling water pump and the electric cooling fan continue operating to prevent overheat damages of the engine after the system-off.